Experimental Study On Transcranial Nerve Stimulation Based On Magneto-Acoustic Coupling Effect

Neuromodulation have a great significance to the study of brain function and neuropsychiatric treatment.However,it is difficult to achieve the electrical stimulation of high spatial resolution for specific regions of deep brain about the existing noninvasive neuromodulation methods.Transcranial magneto-acoustical stimulation(TMAS)is the focus of current research as a new type of noninvasive neuromodulation technology due to its high spatial resolution and precise electrical stimulation for deep brain regions.The theoretical basis of TMAS is that the local current can be formed when ultrasound propagation in tissues in the presence of a magnetic field,and the current will affect the electrical activity of nerves.It can be seen that there is ultrasound stimulation in the process of TMAS.and studies have shown that both TMAS and transcranial ultrasound stimulation(TUS)have an effect on nerve activity.Therefore,how different physical fields play a role in neuromodulation is very important for exploring the mechanism of TMAS.Firstly,this paper study and compare the neuromodulation effects of TMAS and TUS on the motor cortex of mice.The results show that TMAS can induced the faster response and induce stronger EMG signals of the motor cortex of mice which compared with TUS.Both the coupled electric field and the ultrasonic field play an important role in the process of modulating the motor cortex.Based on the above study and related research results,this paper study the effect of electrical stimulation and ultrasonic stimulation to mice in the process of TMAS using deaf model mice,which eliminate the effects of ultrasonic field on bone conduction and local biological tissues for mouse cortical activity.The results show that ultrasound stimulation has a stronger effect on the motor cortical nerve activity in mice compared with coupled electrical stimulation under the experimental conditions.Furthermore,this article uses isolated cells to exploration the effect of TMAS on cell activity preliminarily as to study the effect of the coupled electric field on neural activity.The results show that the coupled electric field can cause the trending movement of cells and changes in cell morphology,which provides a reference for further research on the neurobiological mechanism of TMAS.In order to analyze the effect of magnetic-acoustic coupling electric field on biological tissues,this paper detects and analyzes the coupling electric field generated by TMAS in low-conductivity biological tissues.The results show that the measured coupling electric field of the high-conductivity material is basically consistent with the simulation results.The measured coupling electric field of the low-conductivity biological tissue material is smaller than the simulation result,which indicated that there is still more work need to be done to model and simulate the multi-physics coupling process of TMAS for the low-conductivity biological tissue under the more complex electromagnetic and mechanical conditions.Finally,the work of this paper is summarized.TMAS is a complex stimulus method that combines magnetic and ultrasound.In this paper,the effect of coupled electrical stimulation and focused acoustic stimulation on neural tissue in TMAS is analyzed by experimental studies,and the mechanism of TMAS neuromodulation is discussed.These work laid an experimental foundation for the application of TMAS to noninvasive and precise stimulation of brain nerves,and helped to promote the in-depth development of precision brain science research and precision encephalopathy treatment.